Swine flu update HCFI Saturday 2nd may 2009:  The following current case definitions have been provided by the United States Centers for Disease and Prevention and are current as of April 29, 2009, said Dr KK Aggarwal President Heart Care Foundation of India and Director IMAAKN Sinha Institute. . A confirmed case of swine H1N1 influenza A is defined as an individual with an acute febrile respiratory illness (a measured temperature of 100.4ºF and recent onset of at least one of the following: rhinorrhea or nasal congestion, sore throat, or cough) with laboratory-confirmed swine H1N1 influenza A virus detection by real-time reverse transcriptase (RT)-PCR or culture. A probable case of swine H1N1 influenza A is defined as an individual with an acute febrile respiratory illness who is positive for influenza A, but negative for H1 and H3 by RT-PCR A suspected case of swine H1N1 influenza A is defined as an individual with an acute febrile respiratory illness who: i.         Develops symptoms within seven days of close contact with a person who is a confirmed case of swine H1N1 influenza A virus infection or ii.        Develops symptoms within seven days of travel to a community either within the United States or internationally where there are one or more confirmed swine H1N1 influenza A cases or iii.        Resides in a community where there are one or more confirmed swine H1N1 influenza A cases. Specimens — When swine H1N1 influenza A is suspected, an upper respiratory sample (nasopharyngeal swab/aspirate or nasal wash/aspirate) should be collected as soon as possible. If these samples are not able to be obtained, a combined nasal swab with an oropharyngeal swab should be collected. In intubated patients, an endotracheal aspirate should also be obtained.   Shedding — Patients with swine H1N1 influenza A virus infection are considered to be infectious from one day prior to the development of signs and symptoms until resolution of fever. Individuals should be considered contagious until seven days after illness onset. Longer periods of shedding may occur in children (especially young infants), elderly adults, patients with chronic illnesses, and immunocompromised hosts. Incubation period — although the precise incubation period has not been established for swine H1N1 influenza A infection, it could range from one to seven days, and most likely from one to four days